Process for preparing thiophene and furan derivatives

Abstract

A process for preparing methyl-nitrothenoate and methyl-nitrofuroate by oxidation of the corresponding aldehyde is described.

What we claim is: 
     
       1. Process for preparing nitrated derivatives of the general formula: ##STR3## in which X represents an oxygen or sulphur atom, by the reaction involving the addition of a halogen to a methanolic solution of a base and of an aldehyde of the general formula: ##STR4## in which X has the same meaning as given above, the reaction taking place between 0° C. and reflux temperature of the reaction mixture, wherein the base is an alkali metal carbonate or bicarbonate. 
     
     
       2. Process according to claim 1 whereby the halogen is chlorine, bromine or iodine. 
     
     
       3. Process according to claim 1 wherein the alkali metal is sodium. 
     
     
       4. Proces according to claim 1 wherein X is sulfur and the nitro substituent is located in the 5-position on the ring. 
     
     
       5. Process according to claim 1 wherein X is sulfur and the nitro substituent is located in the 4-position on the ring. 
     
     
       6. Process according to claim 1 wherein X is oxygen and the nitro substituent is located in the 5-position on the ring. 
     
     
       7. Process according to claim 1 wherein X is oxygen and the nitro substituent is located in the 4-position on the ring.